Duplicating grinding machine

ABSTRACT

A machine for simultaneously grinding two independently curved surfaces on a single workpiece. The workpiece is rotated between opposed, independently movable carriages, each of which supports a duplicating roll and grinding means. The duplicating rolls respectively trace the contour of a pair of pattern disks rotating relative to the workpiece and through movable mountings cause their respective grinding means to conform to the surfaces of their respective pattern disks.

United States Patent 1191 Smrcek 1 1 June 4,1974

1 1 DUPLICATING GRINDING MACHINE [75] Inventor: Bruno Smrcek, Neu-Ulm, Germany [73] Assignee: Schiess Aktiengesellschaft,

Dusseldorf-OberkasseL Germany 221 Filed: Apr. 23, 1973 21 Appl. No.: 353,324

[52] 11.8. C1 51/101 R [51] Int. Cl B241) 17/02, B24b 7/00, B241) 9/00 [58] Field of Search 51/64, 101 R, 127

[561 References Cited UNITED STATES PATENTS 1,017,879 2/1912 Landis 51/101 R 2.334338 11/1943 Lang i i 51/101 R 2,373.640 4/1945 lndge et a1. 51/64 2.553.831 5/1951 Musul 51/101 R FOREIGN PATENTS OR APPLICATIONS 431,052 7/1926 Germany 1. 51/101 R Primary Examiner-Othell M. Simpson Attorney, Agent, or FirmYeager, Stein & Wettach [57] ABSTRACT A machine for simultaneously grinding two independently curved surfaces on a single workpiece. The workpiece is rotated between opposed, independently movable carriages, each of which supports a duplicating roll and grinding means. The duplicating rolls respectively trace the contour of a pair of pattern disks rotating relative to the workpiece and through movable mountings cause their respective grinding means to conform to the surfaces of their respective pattern disks.

2 Claims, 2 Drawing Figures DUPLICATING GRINDING MACHINE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a duplicating grinding machine; more particularly to a machine for simultaneously grinding two independently contoured surfaces on a workpiece in conformance with a predetermined pattern.

2. Description of the Prior Art Machines for grinding a contoured surface on a workpiece in accordance with a predetermined pattern are known. In general, these machines employ wellknown means for tracing the surface patterns of a template and transmitting the identical patterns to a grinding head operating upon a workpiece. The workpiece is clamped into position in the machine by means of an expanding mandrel, chuck jaw, face plate and the like.

There is an increasing demand for grinding different types of curved surfaces on a workpiece, for example, on batten cams. With the known machines, the workpiece is clamped-in and one curved surface is ground by use of a duplicating mechanism such as that just de scribed. Before the second curve can be ground, however, the workpiece must be removed and a new pattern installed. Thereafter, the clamping-in process is repeated. When the two curves have a given relationship to one another such as when both curved shapes extend around the common axis of rotation of the workpiece, it is difficult to ensure this relationship in chronologically successive grinding operations; i.e. whenever new clamping-in is required. Any slight change of angle of the peripheral surfaces of the workpiece that are to be ground brought about by the sec ond clamping-in procedure makes the desired relationship of the two curved shapes to one another no longer accurate. In grinding batten cams, where both positive and negative cam surfaces having a definite angular relationship to one another are required, such misalignment is critical.

There are many other examples of curved surfaces which must be accurately ground including:

1. Face cams, such as outside curves, inside curves, groove cams, for example in sequence switch cams, crank eccentrics, pump housings, tripping cams, housings for Wankel engines, etc.

2. Cylindrical cams, such as bell-shaped cams, drumshaped cams, single or multiple groove cams, e.g. in sequence switch cams, standard controller cylinders, and those for lever engagement (central drift), as well as in threads with variable pitch and depth, etc.

3. Longitudinal curves, such as outside curves and groove curves, e.g. in needle guides, control cranks, (EIC.

SUMMARY OF THE INVENTION The present invention overcomes the disadvantages and objections of the prior art duplicating grinding machines by providing for the simultaneous grinding of two different curve shapes on one workpiece so that when the workpiece has been accurately adjusted and clamped in place, the work piece can be ground without having the curve shapes change in their position relative to one another.

The present invention provides a duplicating grinding machine comprising: a base; a table slidably mounted on the base; means mounted on the table for releasably engaging a workpiece and rotating the workpiece about its longitudinal axis; first and second pattern members adapted for rotation relative to the workpiece; first and second duplicating carriages supported by the base on opposite sides of the workpiece axis for relative move ment normal thereto; first and second duplicating roll carriages disposed on opposite sides of the workpiece and supported by the first and second duplicating carriages, respectively, for movement relative thereto and independent of each other; first and second duplicating rolls adjustably mounted on the first and second dupli eating roll carriages, respectively, and adapted for contact with the first and second pattern members, respectively; first and second grinding carriages disposed on opposite sides of the workpiece and supported by the first and second duplicating carriages, respectively, for movement relative thereto and independent of each other; and first and second grinding means adjustably mounted on the first and second grinding carriages, respectively, and adapted for contact with the surfaces of the workpiece in conformance with the respective contacts of the first and second duplicating rolls with their respective pattern members. Preferably, the present invention further comprises: grinding wheel duplieating means mounted on the table in axial alignment with the workpiece and spaced therefrom, the grinding wheel duplicating means being adapted for contact with the first and second grinding means by movement of the table.

Other details and advantages of the present invention will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of the duplicating grinding machine of the present invention, looking in the direction of the axis of the rotational workpiece; and

FIG. 2 is a plan view of the machine of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, the present invention includes a base 1 having a box-shaped cross section, cruciform when viewed from above. Base 1 has heavy supporting walls and ribs (not shown) to give the machine the necessary rigidity and freedom from vibration. Extending horizontally at right angles to the plane of FIG. 1 is table 2 which is movably mounted to base 1 in tempered and ground, massively proportioned roller guides. The roller guides permit movement of table 2 along its longitudinal axis relative to base 1. The roller.

guides are protected against the infiltration of cooling water and grinding dust. The movement of table 2 may be accomplished by driving means well known in the art and may include an automatic rapid return feature.

Mounted on table 2 are workpiece gear box 3 and workpiece receiver 4 of any suitable design. Exchangeably secured on the spindle axis of gear box 3 and immediately behind receiver 4 are two duplicating pattern disks 5 and 6. Also mounted to table 2 and axially spaced from workpiece receiver 4 is headstock 7 with its axially extendable and withdrawable headstock center 8. A workpiece 9 (in this case a batten cam spindle) is clamped between headstock center 8 and workpiece receiver 4; workpiece 9 is rotatably driven by gear box 3. As illustrated in the drawings, two batten earns 10 and 11 are being ground on workpiece 9.

On the opposite side of headstock 7 from workpiece 9 and axially aligned therewith is a grinding wheel duplicating device, designated by the general reference numeral 12. Grinding wheel duplicating device 12, which is mounted on table 2, consists of two separate grinding wheel duplicating devices of the type wellknown in the art.

Mounted to base 1 on opposite sides of table 2 are duplicating carriages 13 and 14. Each of duplicating carriages 13 and 14 is horizontally and vertically movable, independent of the other, relative to the rotational axis of workpiece 9. Duplicating carriages -13 and 14 carry grinding spindle carriages '15 and 17, respectively, and duplicating roll carriages 16 and 18, respectively. Each pair comprising a grinding spindle carriage and a duplicating roll carriage (for example 15 and 16) are horizontally movable on their associated duplicating carriage (in this example 13) in two directions at right angles to one another and independent of one another. A grinding wheel spindle head 19 with a grinding wheel 20 and a grinding wheel spindle head 21 with a grinding wheel 22 are secured respectively to grinding spindle carriages l5 and 17. Grinding wheel spindle heads 19 and 21 are driven by belts 23 of associated motors 24.

Duplicating roll stands 25 and 26 with duplicating rolls 27 and 28, respectively, are mounted on duplicating roll carriages l6 and 18, respectively, co-axially with the axes of their associated grinding wheel spindle heads. Duplicating roll stands 25 and 26 are adjustable relative to the duplicating roll carriages l6 and 18, re-

spectively, which carry them.

Duplicating rolls 27 and 28 are adapted to contact duplicating pattern disks 6 and 5, respectively. Hand wheels 29 serve to adjust this contact when the pattern disks are changed.

Duplicating roll carriages l6 and 18 may be adjusted by means of adjusting spindles. Grinding spindle carriages l5 and 17 may be adjusted by means of adjusting spindles 30. Spindles with hand wheels 31 are provided for the adjustment of the overall infeed of duplicating carriages 13 and 14. The compensating travel may be adjusted by means of hand wheels 32.

The various possibilities of movement are indicated on the drawings by arrows bearing capital letters as follows:

A indicates the rotational direction of workpiece 9;

B indicates the rotational direction of grinding wheels 20 and 22;

C indicates the movement of duplicating carriages l3 and 14 during grinding;

D indicates the manual adjustment of duplicating carriages 13 and 14;

E indicates the movement of table 2 for trimming and for changing the workpiece;

Y F indicates the feeding movement of the individual grinding spindle carriages l5 and 17for the grinding allowance on the surface of workpiece 9; G indicates the manual axial adjustment of the duplicating roll carriages 13 and 14;

H indicates the load on duplicating carriages 13 and 14 during grinding; 1 indicates the load on duplicating carriages l3 and 14 during trimming up;

K indicates the compensating infeed movement;

L indicates the axial grinding spindle adjustment;

M indicates the setting of the mean distance between the duplicating roll and smaller wheel; and

N indicates the adjusting devices for the trimming stop when changing over to smaller duplicating rolls.

The movements described above may be carried out automatically by any well-known means; eg mechanically, hydraulically or electrically, although a mechanical-hydraulic system is preferred.

In the operation of the invention, duplicating rolls 27 and 28 are pressed hydraulically against duplicating pattern disks 5 and 6 which are driven in common with workpiece 9, so that duplicating carriages 13 and 14 will execute the duplicating motion and grinding wheels 20 and 22 undergo a horizontal displacement corresponding to their respective duplicating pattern disks but independently of each other to produce the same curve shape as that on duplicating pattern disks 5 and 6. Duplicating carriages l3 and 14 move at right angles to the grinding axes guided by the two duplicating pattern disks 5 and 6 which correspond to the curve shape of cams l0 and 11 of workpiece 9 that are to be ground. Duplicating pattern disks 5 and 6 are hardened and ground disks. Aside from the clamping-in and the releasing of the workpiece, the grinding process is automatic. The construction of the machine of the present invention thus offers the opportunity for simultaneously grinding two different curve shapes on one workpiece with a single clamping-in operation.

Because the two grinding spindle carriages 15 and 17 and the two duplicating roll carriages 16 and 18 are always movable on their respective duplicating carriages axially and at right angles thereto independently of one another and also independently thereof, both the infeed of the grinding wheels and the sparking-out are selectable. The grinding wheel infeed is selectable either after each rotation of the workpiece or also time-wise, as for example in plunge-cut grinding. The sparking-out can also be selected after a regulatable number of rotations of the workpiece or after a regulatable period of time. For example, in rough grinding, the work is done with a large infeed and a great number of .workpiece rotations; in finish grinding the work is carried out with a small infeed and a small number of workpiece rotations. As in known machines, the number of rotations may be controlled continuously either automatically or by hand.

The grinding spindles are exchangeable so that a grinding spindle whose speed of rotation is appropriate for the desired grinding wheel diameter can be installed for each machining task. Consequently, it is possible to grind with an economical peripheral speed. Grinding can be done on the illustrated machine with the automatic working methods indicated below:

1.-Rough grinding, trimming, finish grinding, sparking-out, switching off, changing the workpiece.

2. Rough grinding, finish grinding, sparking-out,

switching off, changing the workpiece. I 3. Finish grinding, sparking-out, switching off, changing the workpiece.

In procedures 2 and 3 above, trimming is done automatically after a selected number of workpieces. When a workpiece is being changed, table 2 is moved in the direction of arrow E. At the same time headstock center 8 is withdrawn hydraulically so that the workpiece can be changed manually or by means of an automatic loading device.

As stated above, each partial operation of the ma chine, such as rough grinding, trimming, finish grinding, and infeed can be carried out both manually and hydraulically. A built-in compensating infeed serves to compensate for the wear of the grinding wheel when the grinding wheels are trimmed automatically. The drive of workpiece 9 which is supported in workpiece gear box 3 is free from backlash and is actuated by a regulatable hydraulic motor by means of a spring loaded worm gear with two worms as part of the workpiece gear box 3. The hydraulic motor is regulatable so that it is possible to grind with the most favorable speeds of rotation of the workpiece.

Duplicating rolls 27 and 28 are exchangeable and while achieving good shaping accuracy they should have the least possible difference in diameter from the actual diameter of the grinding wheel. When batten cams are being ground for example, a duplicating roll gradation of 0.25 mm is required with a diametrical differential of :t O.l mm. When a duplicating roll is changed, the diameter differential relative to grinding wheels 26 and 22 is compensated for by a corresponding adjustment of duplicating roll carriages 25 and 26. The movable machine parts are journaled by means of roller guides and tempered guide rails. Lubrication is carried out with a conventional oil spray.

As stated above, the workpiece gear box and the headstock which is disposed axially thereto and is axially movable independently of the workpiece gear box are disposed on a common table that can travel axially on the machine base, and can therefore be moved with the table axially out of the range of the grinding wheels. Thus the workpiece, the grinding wheels, and the duplicating pattern disks are readily accessible and exchangeable.

ln order to be able to trim the grinding wheels in one working operation, the grinding wheel duplicating device 12, disposed behind headstock 7 on table 2, is moved past the two grinding wheels by moving table 2. Each grinding wheel carriage with its associated grinding spindle stock and grinding wheel is movable on its duplicating carriage independently of the latter. By

means of the compensating infeed described above,

grinding wheels 2% and 22 are moved in the direction of the truing diamond and are trimmed during this movement without changing the position of the truing diamonds of the duplicating device 12. in order to compensate for the wear of the truing diamonds, the latter have a microadjustrnent device as is customary in grinding wheel duplicating devices.

I claim:

1. A duplicating grinding machine comprising:

a base;

a table slidably mounted on said base;

means mounted on said table for releasably engaging a workpiece and rotating said workpiece about its longitudinal axis;

first and second pattern members adapted for rotation relative to said workpiece;

first and second duplicating carriages supported by said base on opposite sides of said workpiece axis for relative movement normal thereto;

first and second duplicating roll carriages disposed on opposite sides of said workpiece and supported by said first and second duplicating carriages, respectively, for movement relative thereto and independent of each other;

first and second duplicating rolls adjustably mounted on said first and second duplicating roll carriages, respectively, and adapted forcontact with said first and second pattern members, respectively;

first and second grinding carriages disposed on opposite sides of said workpiece and supported by said first and second duplicating carriages, respectively, for movement relative thereto and independent of each other; and

first and second grinding means adjustably mounted on said first and second grinding carriages, respectively, and adapted for contact with the surfaces of said workpiece in conformance with said respective contacts of said first and second duplicating rolls with their respective pattern members.

2. A duplicating grinding machine as recited in claim which further comprises:

grinding wheel duplicating means mounted on said table in axial alignment with said workpiece and spaced therefrom, said grinding wheel duplicating means being adapted for contact with said first and second grinding means by movement of said table.

I DUPLICATING GRINDING MACHINE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a duplicating grinding machine; more particularly to a machine for simultaneously grinding two independently contoured surfaces on a workpiece in conformance with a predetermined pattern.

2. Description of the Prior Art Machines for grinding a contoured surface on a workpiece in accordance with a predetermined pattern are known. In general, these machines employ wellknown means for tracing the surface patterns of a template and transmitting the identical patterns to a grinding head operating upon a workpiece. The workpiece is clamped into position in the machine by means of an expanding mandrel, chuck jaw, face plate and the like.

There is an increasing demand for grinding different types of curved surfaces on a workpiece, for example, on batten cams. With the known machines, the workpiece is clamped-in and one curved surface is ground by use of a duplicating mechanism such as that just described. Before the second curve can be ground, however, the workpiece must be removed and a new pattern installed. Thereafter, the clamping-in process is repeated. When the two curves have a given relationship to one another such as when both curved shapes extend around the common axis of rotation of the workpiece, it is difficult to ensure this relationship in chronologically successive grinding operations; i.e. whenever new clamping-in is required. Any slight change of angle of the peripheral surfaces of the workpiece that are to be ground brought about by the second clamping-in procedure makes the desired relationship of the two curved shapes to one another no longer accurate. In grinding batten cams, where both positive and negative cam surfaces having a definite angular relationship to one another are required, such misalignment is critical.

There are many other examples of curved surfaces which must be accurately ground including:

1. Face cams, such as outside curves, inside curves, groove cams, for example in sequence switch cams, crank eccentrics, pump housings, tripping cams, housings for Wankel engines, etc.

2. Cylindrical cams, such as bell-shaped cams, drumshaped cams, single or multiple groove cams, e.g. in sequence switch cams, standard controller cylinders, and those for lever engagement (central drift), as well as in threads with variable pitch and depth, etc.

3. Longitudinal curves, such as outside curves and groove curves, e.g. in needle guides, control cranks,

etc.

SUMMARY OF THE INVENTION clamped in place, the workpiece can be ground without having the curve shapes change in their position relative to one another.

' The present invention provides a duplicating grinding machine comprising: a base; a table slidably mounted on the base; means mounted on the table for releasably engaging a workpiece and rotating the workpiece about its longitudinal axis; first and second pattern members adapted for rotation relative to the workpiece; first and second duplicating carriages supported by the base on opposite sides of the workpiece axis for relative movement normal thereto; first and second duplicating roll carriages disposed on opposite sides of the workpiece and supported by the first and second duplicating carriages, respectively, for movement relative thereto and independent of each other; first and second duplicating rolls adjustably mounted on the first and second duplicating roll carriages, respectively, and adapted for contact with the first and second pattern members, respectively; first and second grinding carriages disposed on opposite sides of the workpiece and supported by the first and second duplicating carriages, respectively,

for movement relative thereto and independent of each other; and first and second grinding means adjustably mounted on the first and second grinding carriages, respectively, and adapted for contact with the surfaces of the workpiece in conformance with the respective contacts of the first and second duplicating rolls with their respective pattern members. Preferably, the present invention further comprises: grinding wheel duplicating means mounted on the table in axial alignment with the workpiece and spaced therefrom, the grinding wheel duplicating means being adapted for contact with the first and second grinding means by movement of the table.

Other details and advantages of the present invention willbecome apparent from a consideration of the following detailed description taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of the. duplicating grinding machine of the present invention, looking in the direction of the axis of the rotational workpiece; d

FIG. 2 is a plan view of the machine of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT along its longitudinalaxis relative to base 1. The roller.

guides are protected against the infiltrationof cooling water and grinding dust. The movement of table 2 may be accomplished by driving means well known in the art and may include an automatic rapid return feature.

Mounted on table 2 are workpiece gear box 3 and workpiece receiver 4 of any suitable design. Exchangeably secured on the spindle axis of gear box 3 and immediately behind receiver 4 are two duplicating pattern disks 5 and 6. Also mounted to table 2 and axially spaced from workpiece receiver 4 is headstock 7 with UNITED STATES PATENT OFFKIF. CERTIFICATE OF CORRECTION Patent No. 813 I 824 Dated June 4 1 1974 Inventor(s) Bruno Smrcek It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 8, "smaller wheel" should read -the grinding wheel-.

Signed and sealed this 24th day of September 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attestizng;v Officer Commissioner of Patents FORM PC4050 (10439) USCOMM-DC 60376-P69 1* US. GOVERNMENT FRINHNG OFFICE: lBlD 0-366-334. 

1. A duplicating grinding machine comprising: a base; a table slidably mounted on said base; means mounted on said table for releasably engaging a workpiece and rotating said workpiece about its longitudinal axis; first and second pattern members adapted for rotation relative to said workpiece; first and second duplicating carriages supported by said base on opposite sides of said workpiece axis for relative movement normal thereto; first and second duplicating roll carriages disposed on opposite sides of said workpiece and supported by said first and second duplicating carriages, respectively, for movement relative thereto and independent of each other; first and second duplicating rolls adjustably mounted on said first and second duplicating roll carriages, respectively, and adapted for contact with said first and second pattern members, respectively; first and second grinding carriages disposed on opposite sides of said workpiece and supported by said first and second duplicating carriages, respectively, for movement relative thereto and independent of each other; and first and second grinding means adjustably mounted on said first and second grinding carriages, respectively, and adapted for contact with the surfaces of said workpiece in conformance with said respective contacts of said first and second duplicating rolls with their respective pattern members.
 2. A duplicating grinding machine as recited in claim 1 which further comprises: grinding wheel duplicating means mounted on said table in axial alignment with said workpiece and spaced therefrom, said grinding wheel duplicating means being adapted for contact with said first and second grinding means by movement of said table. 